On a recent steamy holiday weekend, customers at a discount grocery store in Evanston loaded their carts with bags of chips, boxes of cookies, 2-liter soda bottles and jugs of fruit punch, among other items, then paid for it all with food stamp credit.

Although some might be surprised to see "nutrition assistance" dollars going to buy food with little nutritional value, it's perfectly legal under federal rules.

Some politicians and health advocates want that to change, saying restricting food stamp purchases to healthier items would encourage better diets, reduce health care costs and make better use of precious tax dollars.

Critics of the idea say such proposals are condescending, probably wouldn't be effective and would stigmatize aid recipients.

Lawmakers in several states, including Illinois, have unsuccessfully pushed bills to make soda, chips and candy ineligible for purchase with food stamps, now called the Supplemental Nutrition Assistance Program. Others have suggested that the program, which is administered by theU.S. Department of Agriculture, could be modified as part of the current farm bill negotiations in Congress.

Supporters of restrictions say they could divert billions of food stamp dollars from junk food to healthier choices, thus saving billions more in obesity-related health care costs, which are predicted by the government to reach $550 billion by 2030.

But just how many taxpayer dollars go to purchase soda, chips, snack cakes and candy each year? The USDA says it has no idea.

"They don't keep track of what is purchased," said Republican state Sen. Ronda Storms of Florida, who introduced a failed bill to restrict junk food purchases. "How then … does the state know whether the purchases are for legal items and not, say, toilet paper, magazines, beer, etc.? Ask that question and you might hear the crickets chirping."

One California watchdog group released a report last week suggesting that this lack of transparency covers up what amounts to billions of dollars in corporate welfare for junk food makers and other companies at a time when Congress is contemplating blanket cuts to a program that provides crucial assistance to hungry people.

"We don't have the information because there are huge economic interests who prefer this information to remain secret," said Michele Simon of Eat Drink Politics, who wrote the report. "It's convenient for USDA to say that we are not authorized to collect information on what people buy with food stamps, but the truth of it is thatWal-Martknows exactly how much was spent on what."

The USDA has opposed restrictions on junk food purchases. Although government data have linked poverty to higher obesity levels and more soda consumption, the department's website says: "No evidence exists that food stamp participation contributes to poor diet quality or obesity."

Simon counters that that is precisely why the data are needed: so the public, researchers and policymakers can determine if the program is contributing to poor diet quality and what programs, if any, can improve that.

USDA representatives say the department is "interested in understanding the food purchase and consumption choices of SNAP clients but relies on other data sources, such as national food consumption surveys" that don't break out statistics on program participants.

Still, in recent months the department has explored a more focused approach. This year, the USDA will launch a feasibility study on gathering point-of-sale data for food stamp recipients. And, according to documents obtained through the Freedom of Information Act, the department has contracted with a private company to examine proprietary retail data with the goal of learning, among other things, "what food items are most frequently purchased with SNAP benefits."

But USDA officials caution that none of that information about food stamp recipients' choices will "tell us anything at all about how they would spend their money if restrictions were imposed."

There's no question that, in a time of lean budgets and class tensions, data on food stamp purchases could be a political hot potato. Simon acknowledges that some observers might use it to "judge and stigmatize" people who use food stamps.

"This would be counterproductive especially when cuts to the program are being considered," she noted in her report. "But fear should not keep us from accurately evaluating the effectiveness of SNAP, particularly given the program's potential for positive impact."

Supporters and opponents of the bans are remarkably diverse groups, with conservative fiscal hawks and liberal public health advocates tending to favor the idea. On the other side are not only large food corporations and anti-regulation conservatives but groups working to feed the hungry.

"We believe that choice leads to dignity and that individual choice should not be impeded," a spokesman for the Greater Chicago Food Depository wrote in an email to the Tribune. "We provide food for hungry people and help people access SNAP without placing judgment on their choices."

Simon and other critics note that many of these groups receive significant funding from food manufacturers. The depository's top donors include Kraft Foods and Sara Lee, and funders of the national Feeding America organization, based in Chicago, include Coca-Cola, PepsiCo and Kraft Foods.

Regarding the potential conflict of interest, Feeding America responds: "We advocate for policies that are in best interests of our clients — the people who use the programs. Our policies are not driven by our donors."

Kraft and Coca-Cola each referred the Tribune to an industry association for comment. A coalition of anti-hunger groups and food-industry associations and lobbyists issued a statement last week, saying: "Rather than limiting food choice and layering over an already complex program with additional hurdles for recipients that may cause stigma and result in confusion and nonparticipation, efforts should focus on nutritional education, access and outreach."

Although public health groups and anti-hunger activists are split on the issue of food stamp restrictions, they both oppose the funding cuts proposed for the program under the new farm bill, which currently stand at $4.5 billion, to $33 billion, over the next 10 years.

Simon says she believes transparency and data-based reforms are the best way to protect the program. The status quo "only makes the program more vulnerable for attack … because the public health implications are mind-boggling," she said.

That statement echoes concerns expressed as early as 1964, when Illinois Sen. Paul Douglas spoke out on the issue during a congressional debate to determine what restrictions would be included in the then-brand new Food Stamp Act:

"I do not want to include Coca-Cola or Pepsi Cola or any of that family," Douglas said. "If we include them, this will be used as propaganda against an otherwise splendid and much needed measure. I want to help the poor and hungry and not sacrifice them for Coca-Cola. The senator (Allen J. Ellender of Louisiana) knows these have no nutritional value — none at all. … The only benefit I see in the present language is that it will increase the sales of Coca-Cola and other cola and soft drink companies."

But in the end, soda was allowed under the food stamp program.

At recent nutrition classes for Chicago families with children at risk of obesity, parents talked about government strategies that might help families with children like theirs make better choices. Most of the participants were low-income, but the organizers did not ask them to disclose whether they received food stamps, which are obtained in Illinois through the Link card.

The parents agreed that educational programs on how to read nutritional labels, eat and shop better could be effective, as could bringing down the price of high-quality fruits and vegetables. But they were split over whether it would help to prohibit purchases of soda and junk food.

"Maybe there should be (restrictions) so kids could be healthier," said Veronica De La Vega, who went on an educational field trip to a Humboldt Park grocery store with her family. "But most people will still do whatever it takes to get what they want. They need the education in order to get healthier habits."

"My friend has the Link card, and she comes over with soda and chips even though I try to tell her that I'm trying not to let my kids eat that," said Lisa Peszat, who attended a class in McKinley Park. "It's just too easy to get it."

"They should really put some restrictions on it so people are more conscious of what they are buying for their kids," said Ana Alejandre.

One food stamp user at a South Side farmers market who asked that her name not be used favored restrictions on junk food but felt they should be balanced with other modifications to the program, which prohibits the purchase of warm and hot foods.

"I find it interesting that with SNAP you can buy 9 million unhealthy things but you can't buy a rotisserie chicken," she said. "I am a big fan of restricting soda, but I would rather they make healthy food more affordable while they discourage the other things. … Where a lot of programs fail is when they are saying 'no this' and 'no that' but they don't give you a doable alternative to encourage a better choice."

Illinois State Sen. Linda Holmes, D-Aurora, last year introduced a bill to restrict food stamp purchases that never even got assigned to a committee for a hearing. She predicts that if obesity-related disease and health care costs continue to rise, so will efforts to add restrictions.

"We need to be creating healthier people in this country," she said. "This is the first generation that may have a shorter life expectancy than their parents, and that is largely due to diet-related problems like obesity, diabetes and high blood pressure. Every session, someone introduces one of these bills, and I think we are just going to keep pushing."

Deltona retiree Paul Jaynes was heartbroken when his 9-year-old Labrador, Cookie, suddenly stopped walking last year. The once-athletic dog struggled to stand and, if she moved at all, collapsed after a few steps.